Cambridge Biotech Firm Idenix Bought By Drug Giant Merck For $3.85B

Idenix works out of the 4th floor of a Kendall Square building, where Merck has offices, too. (Photo BioMed Realty)

Shares of Idenix Pharmaceuticals [Ticker: IDIX] more than tripled in trading Monday morning after the Cambridge firm agreed to be bought by the drug giant Merck for $3.85 billion. That’s a lot of money for a biotech firm that does not yet have drugs approved by the FDA. But the sales price shows how high the stakes are in the fast-growing market for new drugs to treat hepatitis C.

That’s the viral disease on which Idenix has been focusing. Merck is in that market, too. The most promising therapies appear to be combinations of drugs rather than a single silver bullet. And that’s why Merck is trying to own a bigger share of the potential drug cocktail to treat hepatitis C.

Dr. Roger Perlmutter, president of Merck Research Laboratories, said in a statement: “Idenix’s investigational hepatitis C candidates complement our promising therapies in development and will help advance our work to develop a ... treatment as short as possible for millions of patients in need around the world.”

Idenix's CEO Ron Renaud said in a statement that Idenix's market position is stronger by teaming up with a global healthcare giant. "This agreement creates shareholder value by positioning Idenix's strong portfolio of candidates for future success with a leading healthcare company with the experience and commitment to develop fixed-dosed combinations with the potential to impact the global burden of hepatitis C," he said.

The sale of the Cambridge firm is a huge win for a Boston hedge fund, too. The Baupost Group owns 35.4 percent of Idenix.